Increased prevalence of Pneumocystis jirovecii colonisation in acute pulmonary exacerbations of cystic fibrosis

Abstract

This study examined the prevalence of Pneumocystis jirovecii in the sputum of adults with cystic fibrosis during clinical stability and acute pulmonary exacerbation. This was a prospective, longitudinal observational study of patients attending the Manchester Adult Cystic Fibrosis Centre. Sputum samples were analysed for P. jirovecii DNA using PCR at enrolment and up to 5 follow-up visits. Patients were classified as stable or exacerbating using a modified Fuch's pulmonary exacerbation score. 226 samples were tested from 111 patients. P. jirovecii was more likely to be detected in samples at acute pulmonary exacerbation (7/76 (9.2%)) compared with stable visits (3/150 (2%)), p=0.03. P. jirovecii was detected less frequently if patients had received co-trimoxazole within 3 months of sample collection (0% versus 29.7%, p=0.03). Prevalence of P. jirovecii in stable patients is low, but P. jirovecii is detected in approximately 1 in 10 patients experiencing an acute pulmonary exacerbation.